This invention relates to a thermoreversible thickener, more particularly to a thermoreversible thickener which is compounded with aqueous liquids such as water, aqueous solutions of water-soluble compounds, aqueous solutions of water-soluble resins, aqueous dispersions of inorganic substances, and aqueous dispersions of organic substances like latices and emulsions of various resins, and also to compositions compounded with the thermoreversible thickener such as coating compositions, rolling oil compositions, adhesives, printing inks, coating materials for coated papers, binders for nonwoven fabrics and adhesives for carpet backing.